CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total
BALANCE at Dec. 31, 2016	$ 141,377	$ 28,554	$ (82,860)	$ (26,044)	$ (6,101)	$ 54,926
BALANCE (in shares) at Dec. 31, 2016	30,685,017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	0	(19,190)	0	(19,190)
Employee pension plan adjustments	0	0	0	0	881	881
Stock-based compensation expense
Restricted stock	$ 0	948	0	0	0	948
Restricted stock (in shares)	128,810
Net share settlement for equity-based compensation	$ 0	(429)	0	0	0	(429)
Net share settlement for equity-based compensation (in shares)	(184,231)
BALANCE at Sep. 30, 2017	$ 141,377	29,073	(82,860)	(45,234)	(5,220)	37,136
BALANCE (in shares) at Sep. 30, 2017	30,629,596
BALANCE at Dec. 31, 2016	$ 141,377	28,554	(82,860)	(26,044)	(6,101)	54,926
BALANCE (in shares) at Dec. 31, 2016	30,685,017
BALANCE at Dec. 31, 2017	$ 141,377	29,334	(82,860)	(37,528)	(4,510)	$ 45,813
BALANCE (in shares) at Dec. 31, 2017	30,624,407					30,624,407
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	0	(11,578)	0	$ (11,578)
Employee pension plan adjustments	0	0	0	0	485	485
Stock-based compensation expense
Restricted stock	$ 0	502	0	0	0	502
Restricted stock (in shares)	135,568
Net share settlement for equity-based compensation	$ 0	(372)	0	0	0	(372)
Net share settlement for equity-based compensation (in shares)	(207,642)
BALANCE at Sep. 30, 2018	$ 141,377	$ 29,464	$ (82,860)	$ (49,106)	$ (4,025)	$ 34,850
BALANCE (in shares) at Sep. 30, 2018	30,552,333					30,552,333